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Biomedical subjects

R Burrows

Publications and source records attributed to R Burrows.

At least 91 records · Page 5Linked to original sources
PubMed1977

Physicochemical characterization of two serologically unrelated equine rhinoviruses.

The physicochemical properties of two serologically distinct equine rhinoviruses have been examined. Each virus sedimented at approximately 160S but co-centrifugation of the two viruses in a sucrose gradient revealed a small difference in their sedimentation coefficients. The two viruses also have different buoyant densities in cesium chloride. The equine rhinovirus type 1 equilibrated as a sharp peak at 1.45 g/ml whereas the type 2 virus equilibrated as a heterogeneous band with a peak at 1.44 g/ml but ranging in density from 1.41 to 1.45 g/ml. The relative sedimentation coefficients of the two virus RNAs were 35S for rhinovirus 1 and 37S for rhinovirus 2. A limited number of base composition analyses also showed differences between the two virus RNAs. The polypeptide profile of each serotype in polyacrylamide gels was generally similar to those of other picornaviruses but the two serotypes could be distinguished readily from each other.

Antigens, Viral↗
PubMed1975

Experimental studies on equine herpesvirus type 1 infections.

The EHV-1 viruses of fetal origin grew better and had a wider tissue culture host range than those isolated from horses with respiratory diseases. Comparisons of a fetal isolate (F/304) and a respiratory disease isolate (R/NM-3) in partly immune horses showed that the F/304 virus infected horses more readily, grew better in the nasopharynx, was more likely to cause abortion, and was excreted to a greater extent into the environment.

Abortion, Veterinary↗
PubMed1974

Swine vesicular disease: virological studies of experimental infections produced by the England-72 virus.

Pigs exposed to relatively small amounts of virus by intradermal inoculation of the feet or by skin sacrification developed clinical disease. Large amounts of virus were recovered from samples taken from the nose, mouth, pharynx, rectum and the prepuce or vagina during the first week of infection and smaller amounts during the second week. Virus was recovered from the faeces of most animals 16 days after infection and from one animal for 23 days. Pigs in contact with inoculated animals were killed at intervals before the appearance of clinical disease. The distribution and amounts of virus in various tissues indicated that infection has most likely gained entry through the skin or the epithelia and mucosae of the digestive tract. Some pigs acquired subclinical infections in which no virus excretion was detected and no transmission of infection to susceptible pigs took place over a period of 5 weeks.

Animals↗
PubMed1974

Swine vesicular disease: attempts to transmit infection to cattle and sheep.

Cattle and sheep were housed with infected pigs for 11 days. Small amounts of virus were recovered intermittently from the pharynx, milk and rectal swabs of the cattle, but no evidence of subclinical infection was found. Some indication of virus growth in the sheep was obtained in that large amounts of virus were recovered from the pharyngeal region 4 to 7 days after exposure and six of the eight sheep developed significant titres of neutralizing antibody which were maintained in four animals for at least 6 weeks.

Animals↗
PubMed1974

Swine vesicular disease: comparative studies of viruses isolated from different countries.

Seven viruses isolated from outbreaks of swine vesicular disease in various countries between 1966 and 1973 were compared in pigs and infant mice. All produced a similar disease and virus excretion pattern in the pig, although the Italy/66 virus was considerably less virulent than the other viruses. The results of cross neutralization tests of convalescent pig sera and the response of 5-day-old mice to intraperitoneal inoculation indicated minor differences between some viruses. The Italy/66, Hong Kong/71 and France/73 viruses differed from each other and also from the Italy/72, England/72, Austria/73 and Poland/73 group of viruses.

Animals↗
PubMed1971

The growth and persistence of foot-and-mouth disease virus in the bovine mammary gland.

In animals exposed to foot-and-mouth disease virus by indirect contact, virus was recovered from the blood, milk, pharynx, vagina and rectum for variable periods of time before clinical disease was apparent. Virus instilled into the mammary gland multiplied rapidly and virus concentrations greater than 10(7) p.f.u./ml. were recorded within 8-32 hr., depending on the virus strain and dose inoculated. Virus multiplication was accompanied by clinical signs of mastitis but the classical signs of foot-and-mouth disease did not appear for 52-117 hr. Dissemination of virus from the mammary gland occurred within 4-24 hr. and in some animals samples taken from the pharynx, mouth, nose and vagina contained virus for periods up to 97 hr. before the appearance of vesicular lesions. Virus production in the udder declined with the appearance of virus neutralizing activity in the blood and the milk but persisted in some animals for periods of 3-7 weeks. The ability of foot-and-mouth disease virus to persist in mammary tissue was confirmed by the demonstration of virus multiplication in the udders of immune animals.

Animals↗